Dimming Lights.

SlammedLs400 · February 17, 2006

I have a 1994 ls400 and everytime i apply the breaks the headlights dim. I couldnt find anything on this and was wondering if anyone can help or had the same problem? thanks alot.

larryp · February 17, 2006

Suggest you have alternator tested. Sounds like output is marginal when under full load.

RFeldes · February 17, 2006

Also a sign of a waning battery..

Arkansawyer · February 17, 2006

What larryp said. Go to a shop and let them test it. They can do this just by hooking up to the battery. Turn your lights on the A/C etc.

Didn't want to replace it with aftermarket so I bought a used Lexus alt. on ebay and had a local shop rebuild it. Still have my old alt. and if I ever have the dreaded power steering leak will just rebuild it and swap out again.

Do a search on alt. as if you have them rebuild will need to make sure the shop replaces the "slip ring brushes" seems to be the main wear item in the alt. per wwest

dsmlexus · September 30, 2006

My '92 started doing the same thing except the radio also cut out until I released the brake. Then it came back on.

I had some recent service and had them check the battery too. It was marginal as the alt. was fine. I noted that this only started happening recently and after I had driven the car for about five minutes it would stop doing this wierd little electrical adventure. I reasoned this is because I had a good alternator that would recharge the battery just enough that when it was called upon it would provide the charge current required for short periods with a load on it, but those little hot wired items we have on are cars just zap a weak battery after it sat for an overnight let's say. My car would start fine but exibit that weak battery for a few miles. Interesting. Anyway, I think someone else on here also noted that they have never had a battery last more that 3 years and I would second that. I don't thing I have had one last more that 2.5.

VBdenny · October 1, 2006

I had a battery last only 3 years and then sometimes the car would not start after sitting for a few days (usually at the airport). I put in a new one from Costco for around $70 and it has been great ever since.

These cars seem to use a ton of current at startup which I guess puts a strain on the battery. When a battary is compromised many other strange symtoms can appear. I would start with a new battery and go from there.